Yes, pa is a Scrabble word!

Noun

1. An informal term for a father; probably derived from baby talk

2. A short-lived radioactive metallic element formed from uranium and disintegrating into actinium and then into lead

3. A unit of pressure equal to one newton per square meter

4. A Mid-Atlantic state; one of the original 13 colonies

5. An electronic amplification system used as a communication system in public areas